Stories similar to gdm-restart command not found in CentOS 6

I just upgraded from 20 to 22 using FedUp. All seemed to go ok but there was no available driver for my nvidia card due to revision incompatibility with kmod-nvidia. I have a driver from Nvidia's site so I decided to install it. It requires that no xwindow be running during install.

I opened a console using 'ctrl-alt-f2' as root and entered the telinit 3 command.

I was trying to debug my linux boot process. If I set default runlevel to 2 or 3 my system hangs without giving me prompt. So I was able to get to runlevel 1 via kernel parameter. and ran all scripts in rc2.d via service ***** start/stop commands and it was fine. But if I do a telinit to runlevel 2 or 3. I cant see my shell prompt. So what is the diff between to approaches ?